A young woman accused of causing the death of her sister in a car crash was in tears today as she told a jury how their brother died serving in Afghanistan months before the incident.

Rosie-Ann Stone, 21, took to the witness box to describe how Jennie Stone, 28, died when her blue Peugeot 206 car hit a tree next to the A165, near the village of Fraisthorpe, in East Yorkshire, on February 18 last year.

Wiping away tears from time to time, Stone explained how she was in her own car and had pulled out to overtake a slow-moving lorry when she felt the car collide with another vehicle, which "skimmed" her Vauxhall Astra.

She said she suddenly "twigged" it was her sister driving the other car.

Moments later, Stone told the jury at Hull Crown Court, Jennie's car veered in front of the lorry and crashed into a tree.

The defendant, who denies causing her sister's death by careless driving, began her evidence on the third day of her trial by answering questions from her barrister Patrick Palmer about her family.

She had to stop briefly to compose herself as she explained through her tears how her brother Greg was killed while serving in the British Army in Afghanistan in June 2012.

Private Gregg Stone, of the 3rd Battalion, The Yorkshire Regiment, was shot while on active service.

His sister told the court how all her family, including her parents and her surviving three brothers, were in court to support her.

And she explained to the jury how they were all wearing red jackets given to the family by her brother's colleagues in Burma Company to remember him.

"My brother Greg was in the Yorkshire Regiment, an infantry soldier in Burma company," Stone told the jury.

"It's the company jacket. He was never without his. He wore it all the time.

"When he died his comrades donated their jackets in memory of him to the family. We've all got one."

Asked by Mr Palmer about her sister, Jennie, Stone said: "She was like a mum to me when we were younger. As we got older we were inseparable."

She said they were "incredibly close".

Stone explained how she had driven her sister's son Charlie, now 10, to school in Skipsea earlier that morning with Jennie also in the car.

She told the jury that they had planned to go shopping in Scarborough and she had set off first to get some things from her flat in Bridlington on the way.

Stone said she had no idea Jennie was behind her in the queue of traffic building up behind the slow lorry on the A165.

She explained how she looked in her mirror before attempting to overtake the truck and could see nothing to cause concern.

She told the court that she was about half-way past the lorry when she came into contact with another car she had not seen before.

She said it "skimmed" the side of her vehicle so, for a moment, there were three vehicles abreast in the road.

"I saw blue and I saw her (Jennie)," Stone told the court.

"I saw her blond hair and I twigged almost instantly."

She described how her sister's car was travelling faster than hers and it pulled ahead.

But she said: "It suddenly shot across the road. I instantly thought the truck was going to hit her."

Stone said she saw her sister's car hit the tree and stopped her vehicle.

"I was running back down towards the tree to get to her," she said.

"I saw her in the car.

"I was screaming. I tried to get near her and some people took me away.

"I remember screaming something about my sister."

She said she was put in a car and kept away from the crashed Peugeot.

"I wanted to be with Jennie," she said.

"Nobody was with her. She was on her own."

Earlier the jury heard how the defendant described Jennie as a "speed demon" in police interviews.

In a transcript of an interview she had with officers, she said her sister took risks as a driver and had been involved in a number of minor accidents.

She told the police: "I knew she was a speed demon.

"I knew she was comfortable taking risks in her vehicle.

"I think she took a risk and misjudged the situation."

Jonathan Sharp, prosecuting, asked Stone if she thought the tragedy of her brother's death had any bearing on this case. She agreed that it did not.

Mr Sharp also put to Stone that "on any view" of the evidence her sister would have been visible for three seconds as she headed towards her as she overtook the queue of traffic.

Breaking down in tears, the defendant said: "I'm a safe and competent driver and when I looked in my wing mirror the road was clear, hence why I made my manoeuvre."

The jury heard that Stone works as a relief manager for the bookmaker William Hill, travelling around the East Yorkshire area.

In a statement read to the court her mother, Angie, said Jennie was "bubbly" and "family-orientated" and "lived her life for Charlie".

She said her elder daughter "lived her life at 70mph".

But Mrs Stone said her elder daughter's driving made her anxious.

She said: "She used to drive very fast and erratically everywhere."

But she said Rosie-Ann was a "safe and careful driver".

Family friend Paul Kirk told the jury: "I have never seen two sisters get on as well in my life. They were always full of fun. You couldn't part them, really."

Mr Kirk said: "Rosie-Ann is a very sweet girl. She's honest, hard-working, full of fun and reliable.